The present invention relates generally to carrying devices, and more specifically, to plastic handles for self-stick application as assists in gripping and transporting of large, bulky articles, such as oversized books, packages, and the like.
Most households and businesses receive each year a number of large books, such as telephone directories, consumer shopping catalogues, registries, parts catalogues, pages of information tables, charts, maps, etc., bound into large and heavy works of reference. Such directories and catalogues are not only cumbersome to store, but because of their size and weight can be particularly troublesome to securely grip when removing from or placing on a shelf or in a drawer. Because such disposable catalogues and directories are rarely, if ever, supplied with convenient gripping/carrying means, handling of them can be a difficult task, particularly for younger people and senior adults, and especially for the physically impaired. Individuals having, for example, arthritic hands and limbs with inflamed and swollen joints can experience pain in attempting grip and lift such heavy, oversized articles, and in some instances, becomes an almost impossible task.
Hence, various handling assists have been developed, including self-sticking carrying handles for packages, parcels, and various large articles. Preferred embodiments of disposable, self-stick handles providing for seemingly more reliable adhesion properties to articles are disclosed, for instance, in U.S. Pat. Nos. 3,206,104 and 2,158,697. The term "disposable" as used herein is intended to denote the carrying device when affixed to an article is retained in-tact for the expected useful life of the article. Thus, for purposes of the present invention a telephone directory having a self-stick carrying device would be expected to remain in-tact and be functional for the usual period of one (1) year, or until a new directory is published and distributed.
Both of the foregoing patents disclose handles for carrying articles comprising a base portion with an adhesive and a carrying handle bonded thereto, such as by heat sealing. These two piece type carrying handles, compared to single piece strip handles like those disclosed in U.S. Pat. Nos. 4,679,823 and 3,031,349, generally offer more reliable adhesion characteristics because the base section of the device which is bonded to the article provides more contact surface area. A single piece strip handle of the type disclosed in U.S. Pat. No. 3,031,359 provides for less contact surface area since only the terminal end sections adhere to the article.
One might conclude the two piece type handle design of U.S. Pat. No. 3,206,104 is a more reliable device. However, the self-adhering handle of this patent, while providing more contact surface area with the attached article, nevertheless, has been found to have certain shortcomings, making it less than a totally satisfactory carrying assist. In this regard, the hand gripping portion of the device is heat sealed to the contact base strip at its terminal ends. Consequently, when applied to the binding of a heavy object, such as a telephone directory the contact strip on a statistical basis is more prone to delaminate because most of the separation forces are localized at the terminal end sections of the base strip. A carrying handle of this type is more prone to peel from the article prematurely.
The solution to the increased potential for separation from the attached article would seem to be remedied by bonding the hand gripping portion to the base contact strip at points spaced away from the terminal ends. However, we discovered that in fabricating a flexible two piece plastic self-sticking carrying handle comprising a continuous contact base strip and an oval shaped handle portion heat sealed thereto at locations spaced from the terminal ends of the base strip a generally undesirable bowing of the carrying handle occurs, like that illustrated in FIG. 1, the details of which will be discussed further below. Suffice it to say at this point, that bowing of the plastic strip carrying handle makes application to an article a more difficult task, but more importantly, the bowing effect generates low level separation stresses between the contact base strip and the article it is attached to, which can, in turn, cause premature delamination of the handle from the article, particularly when there is some drying or aging of the adhesive. It has also been found that the number of process steps required in fabricating such a two-piece handle make it less economic as a disposable type carrying assist.
Accordingly, it would be highly desirable to have a more reliable carrying handle adapted for self-stick application, and which can also be fabricated more economically than previous devices. Such a carrying assist would be capable for use with heavy articles, economical so it would also be disposable, installed with minimum effort, remain securely in-tact and not be subject to premature delamination from the article it is attached.